Inoue Y H, Taira T, Yamamoto M T
Department of Cell Genetics, National Institute of Genetics, Mishima, Japan.
Genetics. 1988 Aug;119(4):903-12. doi: 10.1093/genetics/119.4.903.
A spontaneous white mutation, white-milky (wmky) of Drosophila simulans is moderately unstable and is associated with a 16-kb long DNA insertion into the white gene. wmky, which is an unstable mutation found in D. simulans, has been genetically analyzed. Among nine spontaneous, partial reversions toward wild type, five were white locus mutations. They are phenotypically different from each other and three show eye color sexual dimorphism indicating a failure of the dosage compensation mechanism. Two w locus mutations whose eye color appeared identical between males and females were also isolated. Of the other back-mutants, three were associated with a recessive suppressor of wmky and one was a semidominant suppressor. These suppressor loci are located on the third chromosome at map positions about 90 and 120, respectively. The suppressor mutations demonstrate specific effects on w locus mutations derived from wmky which lack in the gene dosage compensation. Somatic instability was detected at the frequency of 5.6 X 10(-4) in wmky flies heterozygous for the recessive suppressor and the frequency was increased 10-fold when the suppressor mutation was placed in a different genetic background.
拟果蝇的一种自发白色突变体——白乳色（wmky）具有中度不稳定性，且与一段16kb长的DNA插入到白色基因中有关。wmky是在拟果蝇中发现的一种不稳定突变体，已经对其进行了遗传分析。在九个向野生型的自发部分回复突变中，有五个是白色基因座突变。它们在表型上彼此不同，其中三个表现出眼色的性别二态性，表明剂量补偿机制失效。还分离出了两个眼色在雌雄之间看起来相同的白色基因座突变。在其他回复突变体中，三个与wmky的隐性抑制因子有关，一个是半显性抑制因子。这些抑制基因座分别位于第三染色体上大约90和120的图谱位置。这些抑制突变对源自wmky且缺乏基因剂量补偿的白色基因座突变具有特定影响。在隐性抑制因子杂合的wmky果蝇中，体细胞不稳定性的检测频率为5.6×10（-4），当抑制突变置于不同遗传背景中时，该频率增加了10倍。
